Its not your fault, its the fault of the person who created the model and didn't update it with mesh deformation.

Here is a direct quote from ZModeler forums:

Quote:

Fatal Error SMPA60 was confirmed to appear on models with missing objects. You need to keep the same "extra_*" objects and passanger seat dummies as in original vehicle. At least a complete replace of schafter model does not cause SMPA60 error when missing "extras" were added.

Mesh deformation was updated. Exported models should have the same level of visual damage as original models. You should re-export your models to get them updated.

I suggest you back up your original GTA IV models before you replace them with mods.

i have had this game since its release and never modded it untill a good few months after, after modding some cars and totally messing it up i wanted to uninstall it, ended up doing a format cos i had other issues. after reinstalling my gta iv along with the save files i had backed up i started getting this exact same error msg after two mins of playing, wierd tho i never ever got it during multiplayer. what i done was load my most recent save, get in my infernus out front, then drive up the street and turn the corner, thats when i got the crash, over and over in the same place every time without fail. so i thought maybe it was the car lol well, i got into a sabre out front of my house and drove the exact same way i always get this crash and guess what, no crash :O i drove around for half hour just messing, then went back to my house to get into the infernus, drove down the street and took a right and it crashed with this error again. my guess was that somewhere through modding and the saved game i had backed up lay the issue. so i started a new game, played it pretty far thru with no problems at all. so decied to see what i could do to fix my backed up save which i really wanted to keep in th save file i backed up were several save slots, all slightly different times and dates, i loaded one of the older saves, got into my infernus and drove down the street expecting it for sure to crash, it did not. issue fixed in my book. and i have no doubt it was down to the save file from a install of gta i had modded In no way am i any kind of expert but this msg that follows is for all those idiots who say things like "try buying a new graphics card, try cleaning your disk, try uninstalling and reinstalling" if you have no experience of this issue please for the love of god keep it zipped lol

i have had this game since its release and never modded it untill a good few months after, after modding some cars and totally messing it up i wanted to uninstall it, ended up doing a format cos i had other issues. after reinstalling my gta iv along with the save files i had backed up i started getting this exact same error msg after two mins of playing, wierd tho i never ever got it during multiplayer. what i done was load my most recent save, get in my infernus out front, then drive up the street and turn the corner, thats when i got the crash, over and over in the same place every time without fail. so i thought maybe it was the car lol well, i got into a sabre out front of my house and drove the exact same way i always get this crash and guess what, no crash :O i drove around for half hour just messing, then went back to my house to get into the infernus, drove down the street and took a right and it crashed with this error again. my guess was that somewhere through modding and the saved game i had backed up lay the issue. so i started a new game, played it pretty far thru with no problems at all. so decied to see what i could do to fix my backed up save which i really wanted to keep in th save file i backed up were several save slots, all slightly different times and dates, i loaded one of the older saves, got into my infernus and drove down the street expecting it for sure to crash, it did not. issue fixed in my book. and i have no doubt it was down to the save file from a install of gta i had modded In no way am i any kind of expert but this msg that follows is for all those idiots who say things like "try buying a new graphics card, try cleaning your disk, try uninstalling and reinstalling" if you have no experience of this issue please for the love of god keep it zipped lol

did ur game crash from the safe house near the car dealer place,because i have the same problem and it is annoying the hell out of me. any where in that area crashes my game, i cant go down the road to the left or right after u walk through the door or the the game crashes,every where else in the game seems fine.only if i load another game file.and i did have a backup saved file which i reapplied after reinstalling the game,with mods.but how do i fix this annoying shit

i used to get this after adding car models to cars at save locations. I would be fine until I drove the new imported model to/ near the save point, or try to drive it away from the save point. What you can do
1. delete the save and start again OR
2. find out what car(s) are causing the error, replace the car with the original car (the car you drove to the save point and saved there (this may not be the GTA4 original)), load up the save and move the car out of save point, save again. You can now Import the car again and hopefully save it without any problems. From my experience it seems YOU CANNOT MOD A CAR IF IT'S AT A SAVE POINT!
I don't bother saving cars anymore and have no more problems ;-)
for video 'my smpa60 explained and solved gta4'- http://www.youtube.com/watch?v=r9snCs4z2K4 .

to reclaim your save games not crashing you have to go in and remove any cars from parking spaces in front of houses. and re-save. dont forget the old russian apt where u started! Thats what did it for me- an dont install the new patch it disables all the trainers, car spawners and openIV mod car add-in utility. they wont work.

if you killed playboy and got his mansion, you also will have his orange infernus..when i got his orange infernus i had replaced it as a lambo murcielago lp640 but recently i replaced it to a reventon and thats when i started getting this error, after that i tried reinstalling about 3 times (therefore reverting it back to the original infernus) with no luck. ive just reinstalled the lambo lp640 and it works fine!! no need to delete save game or anything, just go back to the car you had when you killed playboy as the infernus

I have this error. Installed some new cars using SparkIV but when I got on I got into a Faction/Buick Regal mod and drove about half a block then crashed. SMPA60. Tried again going offline, same thing. Now remember, I said I grabbed a car, not took a saved car. I took some poor ass chumps car! I tried to then get a different car, one I didnt mod but same thing. I don't know if going back on a old patch would work but even if it did I dont know how. About the Missing files in the cars, then how come other people get it with no problem, how the maker can show it off in his little video for ten minutes and we can play for one? I think it might be that every time a new modding tool comes out Rockstar gets a new patch. Ill try renistalling and find a way to get an old patch.